In analyzers for testing biological fluids, for example the analyzer shown in U.S. Pat. No. 5,008,082, the patient's biological fluid is supplied via sample tubes to an aspirator, which then delivers it as is to a slide test element, or in some cases, to a dilution cup to which a diluent is added, also by the aspirator. Such diluents are supplied to the aspirator of the analyzer via vials or cups which are periodically refilled by the operator. However, it is important that such vials be re-capped or re-covered when aspiration is not occurring, to prevent evaporation. Covers which have to be removed and reapplied manually are unacceptable since they involve too much operator intervention.
It is known from the prior art to provide for automated means that remove covers of tubes of patient sample. See, for example, DE - GM 3,141,780. However, the covers that are removed are stoppers that are not replaced, so that such automated mechanism contributes nothing to automated means for removing and then replacing the covers of vials of liquid such as diluents. Still further, since the covers in question in the case of the stoppers of the prior art are not permanently mounted in the analyzer, they are potentially parts that can become loose within the analyzer, and therefore a source of jams.
Therefore, there has been a need prior to this invention to provide a device for automated removal and re-application of covers for containers in an analyzer, the covers being permanently secured to the device.